These are not by Mozart, but rather by a composer using his initials. They likely represent contrapuntal exercises in a style reminiscent of the Baroque or early Classical era.
Develop clean articulation and precise fingerwork to clearly delineate the contrapuntal lines.
2 Kontrapunktische Skizzen (K.deest) is rated Henle level 5 of 9 — late intermediate repertoire, roughly ABRSM grades 6–7. In the RCM system it corresponds to about level 7.
You should be comfortable at Henle level 5 — meaning you can already play level 4–5 pieces cleanly. Learning it one level early is possible as a stretch piece, but more than that usually leads to months of frustration.
A typical performance of 2 Kontrapunktische Skizzen (K.deest) lasts about 6 minutes.
2 Kontrapunktische Skizzen (K.deest) is available as free public-domain sheet music on IMSLP — the score is linked directly from this page.